Horse racing is a sport that has enjoyed great popularity over the years. One variation of horse racing, also referred to as low-wheeled harness racing, typically employs specially trained horses which strive to pull rider-mounted sulkies around a race track of prescribed length in the shortest length of time possible.
Typically, a sulky is an apparatus that has two rotatable wheels that are fixedly mounted to a frame, a rear-mounted seat for a rider and at least one forward-mounted shaft that is harnessed to a horse. For instance, U.S. Pat. No. 3,847,408 discloses a single shaft sulky that has two wheels that are supported by axles at the outer ends of a flexible arch, a driver's seat secured to the arch, and a single flexible shaft that extends upwardly and forwardly from the arch to a single point connection on a horse's harness. The two wheels are fixedly mounted to the axles in that the centerline of the wheels'path is always perpendicular to the axis of the axle.
FIGS. 1 and 2 illustrate another sulky of the prior art, as shown in U.S. Pat. No. 4,817,975, which is incorporated herein by reference as fully as if set forth in its entirety. FIG. 1 is a side view that shows wheel 14 which rotates around center hub 30. The wheel assembly is rotatably mounted to U-shaped trailing arm 16 which has an upward-extending rod 18. Rod 18 is inserted and pivots in vertical tube 20, which extends downwardly from frame 12. Seat 22 is mounted to the frame via rearwardly-extending support bar 26, in an adjustable horizontal position that is approximately even with center hub 30 of the wheels and which is about thirty inches above the ground. A pair of forwardly-mounted shafts 28, adjustable to different widths and heights, extend from frame 12 so as to be harnessed to a horse. FIG. 2 is a top view that shows the same features as FIG. 1.
As is well known in the prior art, one of the primary problems experienced by most sulkies is their susceptibility to tipping. This problem is particularly acute when a sulky is travelling around curved sections of the racetrack. This, along with sudden lateral movements of the horse, irregularities in the racing surface or a slightly too aggressive manuever, among many other factors, can result in a vertical tipping force at one of the wheels. If the vertical tipping force is sufficiently large, the sulky may tip, causing the rider to fall from the seat and potentially into the path of oncoming horse-drawn sulkies. Thus, in addition to causing the race to be lost, a tipped sulky may place a rider in serious danger of injury.
Fixed-wheel sulkies of the prior art typically do not have features that prevent the sulky from tipping, but instead rely on the skill of the rider to manuever the apparatus and to regulate the speed of the horse so as to minimize the likelihood of tipping. On the other hand, U.S. Pat. No. 4,817,975 discloses a pivotable wheel feature meant to decrease the likelihood of tipping.
Another problem experienced by sulkies of the prior art is friction between various moving parts of the apparatus. For instance, prior art sulkies that have wheels that are fixedly mounted to an axle experience undesirable friction between the wheels and the axle, and between the wheels and the surface of the track, as the alternating gait of the horse produces alternating sideway displacement forces thereon. In addition, fixedly mounted wheels experience similar frictional forces caused by sideways displacement forces when the apparatus is pulled around the curved sections of the racetrack. Also, when the sulky is pulled around a curved racetrack, torsional stresses are experienced in the axle carrying the wheels, which restrict the movement of the horse.
These frictional and torsional stresses slow the speed of the sulky in numerous ways. First, they increase the resistance experienced by the wheels of the sulky as they rotate around their axles, thus slowing the rotation of the wheels. In addition, because of the increased likelihood of tipping, a rider is more likely to slow the horse down to avoid a dangerous spill. Also, the frictional forces may interfere with the rolling gait of the horse, causing the horse to misstep, or may cause the horse to tire prematurely.
Thus, there is a need for a sulky which decreases the likelihood of tipping while decreasing undesirable forces experienced by the sulky that slow its progress during a race.